How to Jailbreak Your iPhone 4 Using RedSn0w (Mac) [4.2.1]
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Posted November 23, 2010 at 5:49pm by iClarified
These are instructions on how to jailbreak your iPhone 4 on the 4.2.1 firmware using RedSn0w for Mac. You will only be able to perform a tethered jailbreak at this time. This means you will need Redsn0w's assistance to boot into your jailbroken device.
If you want to jailbreak a lower firmware version you can find the appropriate tutorial here.
Make sure not to update to iOS 4.2.1 if you need an unlock as one is not yet available!
Step One Create a folder on your desktop called Pwnage
Download RedSn0w from here and place it in the Pwnage folder. Likewise, download the latest 4.2.1 firmware from below and place it in the same folder.
Extract the redsn0w app from the RedSn0w zip file by double clicking it.
Step Two Connect your iPhone to the computer and launch iTunes.
Select your iPhone from the list of devices on the left. Now hold down Option and click the Restore button. Restore is preferred as it won't create any wasted space on your iPhone.
Navigate to the Pwnage folder on your desktop and select the 4.2.1 firmware ipsw. Click the Choose button to continue.
Step Three Once iTunes has finished updating your iPhone to the desired firmware open the Pwnage folder on your desktop and launch the redsn0w application from the redsn0w folder we extracted earlier.
Step Four Once RedSn0w opens click the Browse button
Step Five Select the 4.2.1 firmware ipsw we placed in the Pwnage folder on our desktop then click Open.
Step Six Once the firmware has been verified click the Next button to continue.
Step Seven RedSn0w will now prepare the jailbreak data
Step Eight From this window you can select the jailbreak options you would like.
Make sure Cydia is selected and click the Next button to continue
Step Nine Please plug your iPhone into the computer and make sure its OFF then click the Next button
Step Ten RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here
Hold down both the Home button and the Power button for 10 seconds.
Release the Power button and continue holding the Home button until RedSn0w detects the device.
Step Eleven Your iPhone will now reboot
Step Twelve RedSn0w will then begin uploading the new RAM Disk and Kernel.
Step Thirteen Once this is complete you will be notified that RedSn0w is done. Click the Finish button. When your iPhone finishes rebooting (5 minutes or so) it will be jailbroken with Cydia on the SpringBoard.
IMPORTANT: To use Redsn0w to help you boot back into your jailbroken device simply select Just boot tethered right now from the options window and click Next.
*As usual a big thanks to the iPhone Dev-Team for their hard work and contribution to the iPhone community.
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I have an iphone 4 version 4.2.1(8C148) with firmware 03.10.01, all I want to do is Jailbreak it and not unlock it because I have AT&T. on other comments I've seen that this updates the baseband... will this void my factory warranty and applecare? thanks!!
Hi, i just jailbroken my iphone 4. the cydia is installed, but its white app. not brown as it should be. when i click on it the cydia does not open nor safari. can anyone help me. i have macbook, mac os x leopard.
Hi.
Thanks guys, I am having a problem with jailbreak my iPhone4, I got my iphone a couple of days beforre officially on 4.2.1, tried so many times jailbreak it with redsnow but no success.
what happens? after this procedure my iPhone4 reboots then everything is well, Cydia is white icon and when i press on it nothing happens.
Any respond and idea will be nice and appreciated.
regards
i Jailbroke my iphone 4 [version 4.2.1(8C148), firmware 03.10.01] using the latest Redsn0w mac 0.9.7b5 but having problem with Skype not loading. I tried the jailbreak process again to see if I was not doing it right but all apps seems to working fine except Skype and Watsapp. Just wanted to inform the dev team about the glitch. Thanksks for all the great work.
ive tried downloading the restore software but it shows it will take several hours to download - why is this? is there a different link i can use? thanks!
Hi..
I've got an unlock iphone and it was already running 4.2.1 without JB.
I tried to JB with redsn0w and followed all the steps in the tutorial, but when the iphone is doing its first reboot while in the process, it freezes..
I reboot it manually and start it back.. and i use the redsn0w app so that the phone start.. but when he starts, i don't have any network carrier :(
and i can't even do a restore via iTunes, cause it says that my device isn't compatible..
how can i solve this out ?
thanks!
Hey Guys,
I have an iphone 4 i did jb but when i put the ship to another company it doesnt work. so, i still cant use my iphone with different company provider.
Could u guys please help me out?
Tks
Arturo
Hello Iclarified team
Thank you for your support. I got it, with jailbreak was OK.
Next question , how i can unlock my phone ? sorry for my disturb
by the way my baseband before upgrade was 01.59 and now 03.10.01 it's ok or no ?
Is there available jailbreak for iPhone4 with IOS 4.2.1 on OS Tiger 10.4.11?
I downloaded the Redsnow jailbreak for iPhone4 IOS4.2.1 but when I double click it it say
" it is not supported in this architecture?."
Thanks.
all, I think the first step is that you need to upgrade the OS to 4.2.1 completely. Then, you can follow this procedure to JB your iphone 4. Otherwise, it might not work. This is my experience for sharing.
I just got an iPhone 4 on Mon and had a problem with the JB. I used Pwnage to JB my 3G with no problem, but can't get past Step 2 here for Redsn0w. Exact Message is: The iPhone "NAME REMOVED" could not be restored because the firmware file is not compatible" with the options of [More Information] or [OK]. Anyone know the remedy for this? I'd really like to fix this.
I did use Firefox. I am running OS X 10.6.4 Snow Leopard and thus do not have IE.
I will try again, however, the only real need I have for JB is SBSettings so I can easily toggle brightness, Wi-Fi and Bluetooth and I guess if I ever need to unlock(even though there isn't one currently available for iPhone 4 firmware on 4.2.1).
Hello...!!!
i jail broke my iphone and i made a cydia on my iphone 4, but when i rebooted it, cydia didnt work anymore! :(
( i tried to do that about 5 times!!! )
.
.
.
Any Help?!?!?!?!?!?!